GPC3 and hepatocellular carcinoma: The tetravalent FLEX-NKTM NKE scaffold is comprised of bivalent Fab2 antigen binding domains, and the flexible hinge and linker in CYT-303 enabled sub-nanomolar binding affinities and high avidity binding for both NKp46 and GPC3 targets while simultaneously engaging NK cells and HCC tumors to mediate NK cell-redirected killing of tumors.